But still, given that cell phones were supposedly invented because of the Star Trek "communicator", I'm surprised nobody's managed to invent phasers yet, especially ones with a "stun" setting for police, to replace Tasers.

You Star Trek nerds are wwwwaaaaaaaayyyy behind the curve here. People have been using these toys in combination with "blue ray" blue/violet lasers to make actual cutting/burning lasers for some time. Get with the times, suckas!